416 Carboniferous System of the United States. 



verdure by the JSToeggeratliia, Lepidodendron, Sigillaria, and 

 numerous families of ferns, always considered reliable coal 

 plants. Carboniferous reptiles walked the sandy shores, and 

 insects floated on the evening air. Other palseontological evi- 

 dence, drawn from the marine fauna, tends in the same direction 

 to wliich the previous statements of this paper lead us, viz, ; to 

 cany the base of the carl)Oiiiferous system three thousand feet 

 nearer the foundations which the fathers erected. It includes 

 all the workable seams of coal. The more safely may we travel 

 in this direction when we take into the elements of our reason- 

 ing that in all the vast thickness of rock strata, which we should 

 add to the carboniferous, there is no unconformity, but a regular 

 sequence in the order of deposition, over a large portion 

 of the American continent, untouched by any disturbing 

 causes. 



While we dig deeper for the carboniferous foundations, may 

 we not carry the structure higher, and find the roof-tree hidden 

 near the TriassiG f In pursuing the geological investigations 

 of Missouri, Maj. Hawn crossed over into Kansas and brought 

 back rich trophies as the result of his geological foray beyond 

 the borders. Upon investigation these trophies were found to 

 be fossils of the Permian type. About the same time Mr. Meek 

 made the same discovery. Prof. Swallow soon followed with 

 confirming evidence from observations from the west of Mis- 

 souri. Prof. Hall has also identified fossils as belonging to the 

 Permian. Dr. Shumard made similar discoveries in the Gua- 

 delupe Mountains, Texas. 



The coal-bearing rocks west of the Mississippi are divided 

 into upper and lower. Above the upper lie the coal measures 

 of Kansas, one thousand feet thick, having within them many 

 seams of coal. Above these, and still higher, lie about eight 

 hundred feet of limestones, shales, clays, cherry layers, and 

 sandstones. All these depositions lie conformable to each other. 

 The fossils gradually grade into each other, from the lower into 

 the upper carboniferous, and from the latter into the lower Per- 



